In the manufacture of an electronic device such as a semiconductor device, there has been conventionally employed a process of etching an etching target layer by exposing a processing target object to plasma which is generated by using a plasma processing apparatus.
As an example of the etching target layer, an organic film may be used, as disclosed in Japanese Patent Laid-open Publication No. 2001-358218 and Japanese Patent Laid-open Publication No. 2002-252222, for example. In the plasma etching described in these documents, plasma of a processing gas containing a nitrogen gas (N2 gas) and a hydrogen gas (H2 gas) is generated, and the organic film is etched by attracting ions to the processing target object with a bias power. That is, in this plasma etching, the organic film is etched mainly by using a physical impact of the ions on the organic film, i.e., by using a sputtering effect with the ions.
Patent Document 1: Japanese Patent Laid-open Publication No. 2001-358218
Patent Document 2: Japanese Patent Laid-open Publication No. 2002-252222
Meanwhile, in the plasma etching of the organic film, it may be required to suppress damage on an underlying layer of the organic film. According to the plasma etching method described in the aforementioned documents, however, it is difficult to suppress the damage on the underlying layer.